This application requests funding for the establishment of the Yale Skin Disease Research Core Center (YSDRC), which will bring together a collaborative, multidisciplinary group of 25 independent Investigators (as well as 19 other Associate Investigators and Consultants) based in the departments/divisions of Dermatology, Biology, Cardiobiology, Comparative Medicine, Endocrinology, Human Genetics, Immunobiology, Molecular Biophysics and Biochemistry, Oncology, Pathology, Pediatrics, Pharmacology, Plastic Surgery, Pulmonary Medicine, and Therapeutic Radiology, all sharing a commitment to advancing understanding of the etiology and pathogenesis of skin diseases through investigation of both the normal and pathologic structure and function of skin. YSDRC research activities will center around three major themes: T cell lymphoma and physiologic T cell:skin interactions; the biology of melanocytes and melanoma; and the growth and differentiation of normal and malignant keratinocytes. Three Core units, each interacting with other Yale resource facilities will be established: Molecular Analysis; Cell Culture; and Tissue Acquisition and Distribution/Biological Structure and Function. The YSDRC pilot/feasibility program will enhance the development of new interdisciplinary skin-related investigation by requiring that projects involve substantive collaboration between investigators with complementary interests. The YSDRC enrichment program provides multiple opportunities to develop new national as well as institutional collaborative studies. These facilities/programs will thus each contribute to achieving the YSDRC's principal goal of creating an environment which will greatly amplify our understanding of basic cutaneous biology as well as of a broad variety of skin diseases. To achieve that goal, the specific aims of the YSDRC are to: 1) stimulate new multidisciplinary interactions; 2) stimulate new investigators to become involved in one or more areas of YSDRC research; 3) capitalize on potentially important new research opportunities through interdisciplinary pilot/feasibility projects; 4) organize time-consuming, expensive techniques and procedures into cost-efficient core facilities used by multiple investigators; 5) provide a rich training environment; and 6) foster national and international collaborations.